1. Field of the Invention
This invention relates to improvements in launching apparatus and more particularly, but not by way of limitation, to a launching device for admitting single spheroids, or the like, into the interior of a pipeline in a sequential relationship.
2. Description of the Prior Art
Pipelines are in widespread usage today for transporting many fluids from one location to another. For example, pipelines are widely used for delivering gas and oil products from the oil well site to the handling or processing plant. The movement of natural gas through a pipeline presents many problems, and one particular problem is the handling of the condensation in the pipeline as the gas stream flows therethrough. The condensation collects in each of hundreds of sags inherent in a pipeline crossing uneven terrain, and the condensate contained within each sag becomes an impediment to the flow of the gas stream through the line. In order to move this condensate through the pipeline it has become the usual practice to move a spheroid, commonly known as a "pig", through the pipeline to force the condensate therethrough. The pig is normally propelled through the pipeline by the pressure of the fluid within the line, such as the gas stream itself, and has proven to be an expedient means for solving the problem.
The pipeline usually comprises a plurality of progressively larger or smaller diameter pipe sections and it is desirable to inject a pig or spheroid at multiple internals along the pipeline in accordance with the diameter variances. In addition, the pipeline may extend through long distances over the country side or open spaces and is frequently unattended. It is, therefore, desirable to provide launching devices at the desired intervals along the pipeline which may be either manually or automatically actuated for injecting the pigs into the interior of the line.
Many devices have been developed for launching the pigs into the pipeline, such as that shown in the Harold N. Eagleton U.S. Pat. No. 3,169,263, issued Feb. 16, 1965, and entitled "Sphere Launching Apparatus". These devices are efficient in operation and solve the problem in a facile manner. However, there are certain disadvantages in the presently available launching devices in that they are normally provided with an integral valve incorporated in the apparatus, or the device must be used in combination with a particular valve, and thus requires the owner of the pipeline to purchase a special valve for installation of the device rather than utilize the normal valves he may have at hand or in stock. Thus, the cost of installation of the launching device is increased and the necessity for the procurement of a special valve may increase the time required for the installation thereof.